To vdragon(紫龙):应该不是你说的问题,我在JDeveloper中调试可以通过啊!有如下错误:Error: 500 Location: /jsp-test/jsp/faq-test.jsp Internal Servlet Error:javax.servlet.ServletException at org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:459) at jsp_0002dtest.jsp._0002fjsp_0002dtest_0002fjsp_0002ffaq_0002dtest_0002ejspfaq_0002dtest_jsp_1._jspService(_0002fjsp_0002dtest_0002fjsp_0002ffaq_0002dtest_0002ejspfaq_0002dtest_jsp_1.java:105) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:119) at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) at org.apache.jasper.servlet.JspServlet$JspCountedServlet.service(JspServlet.java:130) at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.java:282) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:429) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:500) at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:405) at org.apache.tomcat.core.Handler.service(Handler.java:287) at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372) at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:812) at org.apache.tomcat.core.ContextManager.service(ContextManager.java:758) at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java:213) at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416) at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:501) at java.lang.Thread.run(Thread.java:484)Root cause: java.lang.NullPointerException at jsp_0002dtest.jsp._0002fjsp_0002dtest_0002fjsp_0002ffaq_0002dtest_0002ejspfaq_0002dtest_jsp_1._jspService(_0002fjsp_0002dtest_0002fjsp_0002ffaq_0002dtest_0002ejspfaq_0002dtest_jsp_1.java:93) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:119) at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) at org.apache.jasper.servlet.JspServlet$JspCountedServlet.service(JspServlet.java:130) at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.java:282) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:429) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:500) at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:405) at org.apache.tomcat.core.Handler.service(Handler.java:287) at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372) at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:812) at org.apache.tomcat.core.ContextManager.service(ContextManager.java:758) at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java:213) at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416) at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:501) at java.lang.Thread.run(Thread.java:484)
应该是rs==null; 你的推断有问题,ResultSet rs=sql_bean.executeQuery("select * from forum_user");执行不报错并不能说明数据库连接没问题,因为你在bean中把exception都catch了,如果出错,返回的就是null,不然你可以注释掉while(rs.next()){ out.println("<li>"+rs.getString(1)+"</li>"); } 然后把rs打印出来看看
可以了吗?/*--by bookbobby(书呆)-+
| |
| 你说爱我只是习惯 |
| 再也不是喜欢 |
| 我给你的爱 |
| 已不再温暖 |
| |
+--by bookbobby(书呆)-*/
建议:
1。select * from forum_user 返回的结果是什么,是不是为空?
2. 将while(rs.next()){
out.println("<li>"+rs.getString(1)+"</li>");
}
这个放到try{}catch(Exception e){}里面调试,如果还不行,在对上一句进行类试处理。
3.检查是否能正确连到数据库。
4.祝你好运!
只是要原程序中把 while(rs.next()){
out.println("<li>"+rs.getString(1)+"</li>");
}
这两行注释掉就没问题的,可见"ResultSet rs=sql_bean.executeQuery("select * from forum_user");"这句没问题(就说明数据连接没问题),再帮我想想!
谢谢两位!
是不是第一列的类型不是String,然后是null,在toString()的时候出现异常
Location: /jsp-test/jsp/faq-test.jsp
Internal Servlet Error:javax.servlet.ServletException
at org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:459)
at jsp_0002dtest.jsp._0002fjsp_0002dtest_0002fjsp_0002ffaq_0002dtest_0002ejspfaq_0002dtest_jsp_1._jspService(_0002fjsp_0002dtest_0002fjsp_0002ffaq_0002dtest_0002ejspfaq_0002dtest_jsp_1.java:105)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:119)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.jasper.servlet.JspServlet$JspCountedServlet.service(JspServlet.java:130)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.java:282)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:429)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:500)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:405)
at org.apache.tomcat.core.Handler.service(Handler.java:287)
at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372)
at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:812)
at org.apache.tomcat.core.ContextManager.service(ContextManager.java:758)
at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java:213)
at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416)
at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:501)
at java.lang.Thread.run(Thread.java:484)Root cause:
java.lang.NullPointerException
at jsp_0002dtest.jsp._0002fjsp_0002dtest_0002fjsp_0002ffaq_0002dtest_0002ejspfaq_0002dtest_jsp_1._jspService(_0002fjsp_0002dtest_0002fjsp_0002ffaq_0002dtest_0002ejspfaq_0002dtest_jsp_1.java:93)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:119)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.jasper.servlet.JspServlet$JspCountedServlet.service(JspServlet.java:130)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.java:282)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:429)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:500)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:405)
at org.apache.tomcat.core.Handler.service(Handler.java:287)
at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372)
at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:812)
at org.apache.tomcat.core.ContextManager.service(ContextManager.java:758)
at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java:213)
at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416)
at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:501)
at java.lang.Thread.run(Thread.java:484)
你的推断有问题,ResultSet rs=sql_bean.executeQuery("select * from forum_user");执行不报错并不能说明数据库连接没问题,因为你在bean中把exception都catch了,如果出错,返回的就是null,不然你可以注释掉while(rs.next()){
out.println("<li>"+rs.getString(1)+"</li>");
}
然后把rs打印出来看看
******但是在JDeveloper下调试可以通过啊!******
try{
while(rs.next()){
out.println("<li>"+rs.getString(1)+"</li>");
}
}catch(Exceptione e){
out.println("saper错误一"+e.toString());
}
这样你看看!把那两行注释掉,不能说明 ResultSet rs=sql_bean.executeQuery("select * from forum_user");这一行返回的值是什么,如果是null,那么while(rs.next()){
out.println("<li>"+rs.getString(1)+"</li>");就会报空异常了。
谢谢各位了!